Formerly part of Highway 17, until segments west of Highway 417 were downloaded in 1998. Has several former alignments, such as Chemin de la Baie (Bay Road) and Rue Laurier (Laurier Street) in Rockland, an abandoned alignment near Clarence, and CR 8 from CR 17, north to Clarence ("Old Highway 17"). This continues close to the Ottawa River as CR 55. Even older alignments lead off into the Ottawa River, having since been flooded by the Carillon hydroelectric dam project in the late 1950s.

Former alignment of Highway 17. Even older alignment leads off into the Ottawa River (as Chemin du Domaine/Domaine Road), having since been flooded by the Carillon hydroelectric dam project in the late 1950s.